1. Technical Field
The present invention relates generally to an electrical signal transmission member in an electro-mechanical system, and more particularly to a carbon brush holder.
2. Description of Related Art
In an electro-mechanical system, slip rings and carbon brush holders are commonly used for transmitting electric current or signals to and from rotary parts in the electro-mechanical system.
Generally, a slip ring assembly includes a plurality of conductive slip rings and a plurality of insulating rings, wherein each of the conductive slip rings is arranged between two of the insulating rings. As shown in FIG. 1 and FIG. 2, a conventional carbon brush holder 1 includes a metal brush frame 2 and two carbon brushes 3. The metal brush frame 2 is made of a metal sheet with high electrical conductivity, and is formed by a punching process. The metal brush frame 2 includes a main frame 2a and two branch frames 2b respectively connected to two ends of the main frame 2a. The two carbon brushes 3 are connected to the two branch frames 2b respectively to abut against a conductive slip ring (not shown) for steadily transmitting electric current or signals.
However, due to the results of the processing method and the finish manufacturing of the metal brush frame 2, an included angle θ between the main frame 2a and each of the two branch frames 2b is prone to being too large, which may leave a gap between the carbon brush 3 and the conductive slip ring. As a result, there may be interference with transmission of electric current or signals.
Moreover, each of the branch frames 2b should be positioned as depicted by the solid line in FIG. 2, but may swing to the position depicted by the dotted line in the same figure because of a lapse of the processing method. Consequently, the two carbon brushes 3 would either fail to precisely contact the conductive slip ring or abut against the insulating ring, which obstructs the transmission of electric current or signals. Such obstructions are particularly problematic for a miniaturized slip ring assembly, since it has a shorter interval between two adjacent insulating rings.